pkenc_gm82

Goldwasser-Micali Public Key Encryption Scheme (Quadratic Residuosity problem)

From: “S. Goldwasser, S. Micali: Probabilistic encryption and how to play

mental poker keeping secret all partial information”

Published in: 14th Symposium on Theory of Computing (1982)

Available from: http://groups.csail.mit.edu/cis/pubs/shafi/1982-stoc.pdf

Notes:

• type: encryption (public key)
• setting: Integer
• assumption: Quadratic Residuosity

Authors:Guillermo Ramos Date:01/2015

class pkenc_gm82.GM82

Bases: charm.toolbox.PKEnc.PKEnc

>>> gm82 = GM82()
>>> (pk, sk) = gm82.keygen(512)
>>> zero = gm82.encrypt(pk, 0)
>>> one = gm82.encrypt(pk, 1)
>>> gm82.decrypt(sk, zero)
0
>>> gm82.decrypt(sk, one)
1
>>> gm82.decrypt(sk, gm82.xor(pk, zero, zero))
0
>>> gm82.decrypt(sk, gm82.xor(pk, zero, one))
1
>>> gm82.decrypt(sk, gm82.xor(pk, one, zero))
1
>>> gm82.decrypt(sk, gm82.xor(pk, one, one))
0

decrypt(sk, c)

encrypt(pk, m)

keygen(secparam)

xor(pk, c1, c2)

pkenc_gm82.isResidue(x, p1, p2)